... so you find the default db.py comments ("Define your tables below") not clear enough, is that correct?
Would changing the default (welcome) db.py to look like something like this help:
#####################---< your tables section >---############################
## Define your tables below, for example
##
## >>> db.define_table('mytable',SQLField('myfield','string'))
....
########################################################################
# your table definitions (define before the Auth Section) #
##
#################---< END your tables section >--############################
#####################-- Auth Section --################################
## Here is sample code if you need:
## - email capabilities
.....